Communication devices may transmit and receive communication data through a communication medium. In one example, the communication medium may be a wireless communication medium where communication data is transmitted and received by communication devices according to a wireless communication protocol. Example wireless communication protocols may include the IEEE 802.11 protocols (e.g., Wi-Fi), Bluetooth protocols according to the Bluetooth Special Interest Group, and Long Term Evolution (LTE). Wi-Fi communications may operate in either a frequency band centered around 2.4 GHz (e.g., 2.4G Wi-Fi communications) or a frequency band centered around 5 GHz (e.g., 5G Wi-Fi communications). LTE is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by Third Generation Partnership Project (3GPP). LTE communications may operate in portions of the licensed frequency spectrum (e.g., between approximately 700 MHz-2.6 GHz; may be known as LTE-L) and may operate in portions of the unlicensed frequency spectrum (e.g., around 5 GHz; may be known as LTE-U).
In another example, the communication medium may be a wired communication medium where the communication data is transmitted and received according to a wire-based communication protocol. Example wire-based communication protocols may include an Ethernet® protocol and/or a Powerline Communications protocol described by the HomePlug 2.0 specification. In yet another example, the communication medium may be a hybrid combination of wired and wireless communication mediums.
Analog signals within the communication devices may undergo amplification during various processing operations. For example, an analog signal may be amplified when a communication signal is received from or transmitted to another communication device. In some cases, as an analog signal is amplified, an unwanted signal may be introduced (e.g., added) to the amplified signal. For one example, as a first signal is amplified, a second signal that is an unwanted harmonic of the first signal may also be amplified. The second signal may couple into a sensitive receive and/or transmit circuit of the communication device and interfere with the transmission and/or reception of the communication data.
For another example, when a communication device is configured for multi-band concurrent operation (e.g., to concurrently communicate with other devices using 5G Wi-Fi/LTE-U signals and using 2.4G Wi-Fi/LTE-L signals), the transmission and/or reception of signals in one frequency band may interfere with the reception of signals in the other frequency band. More specifically, the 2.4G Wi-Fi/LTE-L signals may undesirably couple into the receive circuits used for the 5G Wi-Fi/LTE-U signals, which degrades performance of the communication device.
Thus, there is a need to improve the amplification of analog signals while suppressing amplification of unwanted signals, and thereby improve the performance of the communication device.